Species Nutrition Testolyze Review

Testolyze is a test-booster by Species Nutrition. We’re thrilled that the brand has opted for a fully-transparent supplement facts label with Testolyze but, unfortunately, there are some issues with the dosing of key ingredients…

Species Nutrition Testolyze



Tribulus has a well-documented traditional history of use as an aphrodisiac which has contributed to its reputation as an herbal Testosterone booster. However, despite this reputation, Tribulus has never actually been shown to increase Testosterone in healthy human subjects, and even in infertile (low Testosterone) men has produced lackluster results.

A 2005 study, published in the “Journal of Ethnopharamcology” found that 200mg daily (60% saponin content) had no effect on Testosterone in healthy men. These results were replicated in a 2007 study in which 450mg of Tribulus extract daily failed to influence Testosterone levels in male athletes. Even a 2012 study, this time testing the effects of 6g of Tribulus extract on infertile men, found a less than significant trend towards increased Testosterone.

As a libido enhancer, Tribulus may provide the illusion of increased Testosterone but there is absolutely no evidence to suggest it will increase Testosterone. In fact, there is large amount of evidence to the contrary. Testolyze features 1250mg of Tribulus standardized for 40% Saponins. Such a dose may be highly effective as a libido enhancer, but an actual Testosterone increase is highly unlikely.


D-Aspartic Acid has earned itself a reputation as a Testosterone booster in recent years, but unlikely Tribulus, this reputation is actually warranted. Out of the three human studies done specifically to test the effect of D-Aspartic Acid on testosterone, two have shown a significant increase in testosterone levels.

A 2012 study from “Advances in Sexual Medicine”, the subjects of which were infertile men (initially low Testosterone) found that 2.66g of D-Aspartic Acid was able to significantly increase Testosterone levels when measured after 90 days of supplementation. These results were in-line with those of an earlier (2009) study in which D-Aspartic Acid supplementation raised Testosterone by 42% after 12 days in healthy men (initially normal Testosterone).

However, a 2013 study published in “Nutrition Research” found that athletes who supplemented with D-Aspartic Acid for 28 days showed no difference in testosterone levels.

The researchers in the failed study noted abnormally high levels of D-aspartate oxidase, the enzyme which degrades D-Aspartic Acid, indicating that prolonged supplementation in individuals with healthy Testosterone levels may cause “negative feedback” which reduces the effects.

Ultimately, D-Aspartic acid is an effective short-term Test-booster for healthy individuals with initially normal Testosterone levels, but the effects may fade after a few weeks of supplementation. Those individuals with abnormally low Testosterone levels may benefit from longer term supplementation however.

Testolyze contains 1000mg of D-Aspartic Acid per serving, about a third of what has been shown to increase Testosterone in human subjects. Species Nutrition claims that higher doses of D-Aspartic Acid (3000mg) will result in a Testosterone spike followed by a rapid decline. This is true, but there is absolutely no evidence to suggest that lower doses will lead to a slow and steady increase in Testosterone. In fact, its entirely possible that the 1000mg of DAA will have absolutely no effect on Testosterone at all, so ultimately Testolyze would probably be effective if it contained the proper 3000mg dose.


Muira Puama is a South American shrub which has been traditionally used as an aphrodisiac and erectile agent, though clinical studies are lacking. A 1994 study, published in the “American Journal of Natural Medicine”, found that 1000-1500mg of Muira Puama was able to improve Erectile Dysfunction status in 51% of male subjects after 2 weeks of supplementation. At this time, no studies have directly tested the effects of Muira Puama on Testosterone.

Testolyze contains 425mg of Muira Puama per serving, far less than the 1000-1500mg range used in the above-mentioned study, but possibly still enough to increase sexual desire.


Manganese is an essential trace mineral with a wide variety of implications for human healthy and development. Though it plays many physiological roles in the human body, one of the most important is in the production of sex hormones, like Testosterone. A 2006 study, published in “Reproductive Toxicology”, found that Manganese treatment increased Luteinizing Hormone (LH) and increased Spermatogenesis in male rats.

Although Manganese plays a vital role in Testosterone production, and thus is an important nutrient for maintaining optimal levels, it is entirely possible to get adequate amounts from your diet. Manganese is present in a wide variety of foods including fish, nuts, seeds, and whole grains. So, will the Manganese Carbonate in Testolyze increase your Testosterone levels outright? Probably not, but it may help encourage optimal levels.


Saw Palmetto is a widely used supplement for treating BPH (discussed above) as well as overall prostate health. One cause of BPH is thought to be excess dihydrotestosterone (DHT), which is a byproduct of Testosterone itself. Testosterone is converted into dihydrotestosterone by the enzyme known as 5-alpha-reductase. While Saw Palmetto does appear to act as a 5-alpha-reductase inhibitor in animal models, human studies directly testing its effects on Testosterone are non-existent. The mechanism of action here is perfectly plausible but there just isn’t enough evidence to determine how effective Saw Palmetto really is at reducing Testosterone-DHT conversion.

The lack of human studies make it difficult to interpret the efficacy of the 400mg per serving found in Testolyze.


Maca (Lepidium Meyenii) is a relative of Broccoli, indigenous to Peru, which has historically been used as an aphrodisiac. While frequently included in products aimed at increasing Testosterone, research has confirmed that the aphrodisiac effects of Maca are not caused by an elevation in Testosterone, nor does it have any significant impact on any hormones.

A 2002 study, published in “Andrologia”, found that Maca supplementation increased sexual desires, but that this effect was independent of Testosterone, which stayed the same. These findings were replicated in a 2003 study, published in the “Journal of Endrocrinology”, in which supplementation with 1.5 and 3 grams of Maca extract for 12 weeks had no influence on Testosterone levels in healthy men.

In several human studies, Maca has demonstrated a clear aphrodisiac effect when at least 1.5 grams is consumed. A 2009 study using 2400mg of Maca showed “a small but significant effect of Maca supplementation on subjective perception of general and sexual well-being in adult patients with mild ED.”

A separate 2009 pilot study, this time investigating a potential effect on physical performance, found that Maca supplementation effectively improved physical performance (cycling) in trained male cyclists, while simultaneously increasing sexual desires. Overall, it appears Maca supplementation with at least 1.5 grams may increase sexual well-being and possibly improve certain aspects of physical performance, but will not increase Testosterone.

Testolyze contains a pretty insignificant 160mg dose of Maca, far less than the doses used in all the above-mentioned studies. For that reason, Maca most likely won’t contribute much to the aphrodisiac/libido enhancing potential of Testolyze.


Currently, Stinging Nettle is used to treat inflammation resulting in joint and muscle pain, as well as to treat urinary symptoms of prostate enlargement (Benign Prostatic Hyperplasia). It is claimed (mostly by supplement companies) that Stinging Nettle may indirectly boost testosterone by lowering sex hormone binding globulin (SHBG). SHBG is a protein that binds to the sex hormones (androgen/estrogen), thus rendering them biologically inactive. The term “free testosterone” refers to Testosterone that is not bound to SHBG, and is therefore free to enter cells and activate Androgen receptors.

A 2012 study, published in “Andrologia”, found that Nettle Extract increased serum Testosterone in rats via 5-alpha-reductase inhibition. However, one human study which sought to determine if Nettle was an effective treatment for BPH also measured Testosterone levels and found no such increase. While the mechanism of action exists by which Stinging Nettle could theoretically increase Testosterone, human studies are lacking and the only one we have to go by produced no such results.

The 120mg dose found in Testolyze most likely wouldn’t be enough to convey and Test-boosting benefits anyway, so the value of Stinging Nettle in this formula is pretty questionable.


Indole-3-Carbinol (I3C) is found mostly in cruciferous vegetables (broccoli, brussel sprouts, kale, etc), but has become relatively popular as a dietary supplement for its potential to alter estrogen metabolism, as evidenced in a 1990 study published in the “Journal of the National Cancer Institute” in which 500mg Indole-3-Carbinol administered to humans significantly up-regulated the conversion of estradiol (major estrogen) into its less active counterparts, Estrone and Estriol.

It’s important to understand that the term “Estrogen” is actually an umbrella term that includes several Estrogenic compounds which induce varying degrees of Estrogenic activity. Indole-3-Carinol (and its metabolites) appears to increase the level of 2-hydroxyestrogens (“weak Estrogen”), relative to the other types, 16a-hydroxyestrogens and 4-hydroxyestrogens (“strong Estrogens”), the result of which is less of an “estrogen-like” effect, even though total Estrogen (good and bad) may technically be staying the same.

Testolyze contains a pretty low 75mg dose of Indole-3-Carbinol which seriously brings into question whether it’s even beneficial in this formula.


Diindolylmethane (DIM) is a byproduct created during the digestion of Indole-3-Carbinol, a compound found in vegetables like Broccoli.

A 2011 pilot study found that, when given to human subjects at a dose of 300mg daily for 14 days, DIM produced anti-estrogenic effects. Under different circumstances however, DIM has shown the opposite, meaning it actually has the capacity to increase Estrogen. So, rather than labeling DIM as pro-estrogen or anti-estrogen, it should be considered an estrogen modulator (meaning it has the ability to alter levels of estrogen one way or another).

As discussed above, “Estrogen” actually consists of different compounds, and DIM can facilitate the conversion of “bad Estrogen” to “good Estrogen”, ultimately reducing Estrogen-like effects.

Testolyze contains 75mg of DIM, not a highly effective dose as far as the research is concerned, but it’s possibly that a little extra DIM is created through the metabolism of Indole-3-Carbinol.


Resveratrol is an anti-oxidant compound found in Red Wine (among other things), which is primarily used as an anti-aging supplement. However, for the purposes of Testolyze, Species Nutrition is more concerned with preliminary evidence which suggests Resveratrol may reduce the conversion of Testosterone to Estrgoen via Aromatase inhibition.

A 2006 in vitro study in which Resveratrol effectively reduced the conversion of Testosterone to Estrogen in breast cancer cells (where Estrogen is high). However, no human studies have been conducted to replicate these findings so at this time there is simply not enough to evidence to conclude Resveratrol is an effective Aromatase inhibitor in humans.

Furthermore, Testolyze contains just 25mg of Resveratrol per serving, far less than the concentration used in the above-mentioned in vitro study, as well as most Resveratrol containing products.


Ginger has demonstrated the ability to increase Testosterone concentrations in rats, but human studies are scarce. A 2012 study from the “Tikrit Medical Journal” found that Ginger administered to infertile (low Testosterone) resulted in a roughly 17% increase in Testosterone. However, the dosage of Ginger used was not specified which sort of brings into question the overall quality and structure of this particular study. Given the preliminary support from animal studies, the results make sense, but with only 25mg of Ginger, Testolyze probably contains far less than the dosage used in the above-mentioned study.


The biggest issue we see with Testolyze is a matter of dosage. While it contains several effective ingredients (for both Testosterone-boosting and Estrogen-blocking), mostly of the levels are far less than what has been clinically validated. This all-in-one approach may be a great way to go when adequate doses of each key ingredient are used, but there is no evidence to suggest that small fractions of those doses will have some profound synergistic effect when combined. The addition of Tribulus only muddies the waters further because it may provide the illusion of increased Testosterone (i.e. enhanced libido) without actually increasing it.

Still not sure which testosterone booster is right for you? Check out our Best Testosterone Boosters List!


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